A closer look to those systems shows that all those approaches
still have two major drawbacks:(1)content creation is still a
tedious process and requires expert knowledge and(2)the exist-ing systems have little “intelligence” in the sense of awareness
about the current state of the scene and the user's context. In
particular the latter would be a prerequisite to properly shape the
provided information to the user's needs regarding situation and
level of skills. Information level is identical for all users,and scene/
user-action analysis is absolutely missing.